The present invention relates in general to a diaphragm bellows.
Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.
A diaphragm bellows of a type involved here is used, for example, in vacuum systems for compensating movements of pipe elements or valve movements to prevent leaks, or for applications in measurement instruments to ascertain state variables such as pressure, temperature, throughput, and flow rate. Diaphragm bellows have small spring stiffness and thus a high mobility and can be compressed axially until all corrugations come into full metallic contact and become immobile. Normally, the diaphragm bellows can be compressed axially over a large proportion of the entire operating path (up to 80%) between relaxed center position and compressed blockage.
German Pat. No. 861732 B describes a bellows made of corrugated diaphragm disks, wherein the inner and outer edges are alternately soldered or welded together. A similar diaphragm bellows, comprised of ring-shaped metal sheets, is described in German Offenlegungsschrift DE 1503436 A.
Common to all prior art diaphragm bellows is the need for a welding operation, e.g. by burners, between neighboring diaphragm disks at their smallest and greatest diameter. In general, the manufacture of diaphragm bellows is complicated because diaphragm disks and burner must be repositioned after each completed circumferential welding seam. The welding seams are arranged on a plane which extends orthogonally in relation to the rotation axis and there is no connection between the welding seams.
It would be desirable and advantageous to address prior art shortcomings.